Public open spaces associated with the Mount Gambier Library and Community Centre project incorporates cutting edge Water Sensitive Urban Design (WSUD) strategies as outlined within the Urban Design and Traffic Management Plan created by the City of Mount Gambier and adopted by Council in 2007.
The Plan highlights the many opportunities Council has to develop urban landscapes into green zones that inspire the pedestrian, enhancing the experience at street level and promoting a healthy lifestyle.
Key pedestrian linkages throughout the City were identified within the Plan, giving Council priority zones to ensure a focus for future redevelopment works is fixed on enhancing the quality of surface finishes, street furniture and landscaping elements.
The Civic Precinct, including the Civic Centre and Mount Gambier Library and Community Centre, was identified in the Plan as a key location with cultural, heritage and social significance.
Due to the proximity of the project site to the Cave Garden sinkhole (the City’s original water source) water as a ‘common’ theme was used as inspiration for the WSUD strategies integrated into the Civic Plaza and associated car park.
This project provides an opportunity to promote the City as being committed to water sustainability and protection.
The concept of urban greenery and Water Sensitive Urban Design is not only based on improved aesthetics, but on at least five fundamental benefits for cities as they become denser including:
- increased biodiversity
- reduced temperatures
- cleaner air
- less water run off, minimising flooding and reducing infrastructure
- improved psychological wellbeing for people.
WSUD strategies
The stormwater disposal system is categorised in the following three main parts:
Permeable pavers
Permeable pavers will be used to lower rainfall run off from impervious areas that will ultimately reduce potential downstream flooding.
These pavers are also designed to capture pollutants from stormwater runoff that would otherwise contaminate groundwater or drainage systems. These systems are then used to assist in the biological decomposition of hydrocarbon contaminants while enabling the underground aquifer to be naturally recharged.
Vegetative swales
Adjacent to the permeable pavers are a series of Vegetative Swales that are used as natural filter strips that retain excess runoff from the car park zone not captured by the permeable pavers.
These swales are shallow channels lined with native grasses and sedges that retain pollutants through infiltration and redirect captured excess runoff to a nearby sediment removal pond.
Importantly, the swales are heavily vegetated with grasses, sedges and shade trees for the car park so captured water is able to effectively reach the root zone and naturally hydrate the landscape elements. Only excess runoff able to reach this part of the underground system is directed to the sediment removal pond via an integrated network of perforated subsoil drains.
Sediment removal pond
The final part of the system is the Sediment Removal Pond that captures all of the excessive runoff not infiltrated into the groundwater via the permeable pavers and vegetative swales. This pond, with a cascading open drain, has the capacity to hold runoff for a major storm event and has been designed as a contemporary piece of urban architecture while performing an important civic function.
As a vegetated stormwater receptacle it stores and filters excessive runoff in an attractive urban landscape.
As a demonstration site for future WSUD projects within the Mount Gambier City Centre, it will become a benchmark feature and promote the need for water conservation awareness in a public space heavily frequented by locals and tourists alike.
